What makes a tileset a tileset anyway?
In the most basic form, a tile is just a square of 32x32 pixels placed into a grid. That's really all there is to it; this applies to anything that uses tiles, regardless of the tile size. I'm not a pixel artist though, so I can't really give you a fancy answer. Ripping is pretty easy if you have some graphical know-how, a steady hand, and lots of patience with the eraser tool. What gives you trouble in VX is the autotiles. These are set into a very specific position, and automatically place in certain ways depending on what kind of autotile you're dealing with.
I started placing some things into tiles, but there are some mistakes. n__n; You have to be very careful where the pixels go when making these, since they tile themselves in a pattern.
There's what it looks like in VX. The wall tiles in A4 were actually around 3 tiles high, but I had to shrink them to 2 tiles high so that they'd comply to VX's autotiles. Using autotiling is optional, however, because I could also separate the wall into individual pieces and then map based on that. It's just rather tedious, that's all. I should note that if I did that, it would mean I could probably keep the walls at their original height.
And with the edit to tile A3... I actually had to manually extend it to make it two tiles high, so that it'd fit the autotile specifications. Still, it looks weird when you go higher than 2 tiles with it, so I wouldn't consider it a very good attempt. Someone who has experience with tiles could figure out a better way to format it, I'm sure.
Couldn't I just draw a background within dimensions and make it png and then use it?
You can definitely do this; it's called parallax mapping. There are some tutorials by C7 in the tutorials forum about the topic. Normally I'd go link them, but it's almost 3 in the morning here. @A@ I'm trying to keep a coherent reply before I forget half of what I'm trying to say.
The biggest issue with parallax mapping is passability. I took the palace map from earlier, for instance, and sized it to fix a 32x32 grid...
...Which resulted in some awkward parts.